1. Field
The presently disclosed subject matter relates to devices, systems, and processes useful as a transversely mounted transaxle having a low range gear assembly for use in a vehicle and a vehicle powertrain including the same.
2. Description of the Related Art
Existing powertrains for vehicles include a power source such as an internal combustion engine, electric engine, hybrid power source, and possibly other types of power sources. The powertrains can include a multi-ratio transmission with output shafts oriented in a longitudinal direction or a transverse direction of the vehicle. The front wheels, rear wheels, or all four wheels of existing vehicles can be driven by the power source and transmission.
In order to meet packaging targets and/or weight distribution targets, it is known to integrate the differential assembly with the multi-ratio transmission. Such an integrated assembly is known as a transaxle. The transaxle can be mounted at the rear of a vehicle and the rear driveshaft(s) can be mounted to and pass through the transaxle in the case of a rear-wheel drive configuration for the vehicle. Similarly, the transaxle can be mounted at the front of the vehicle and the front driveshafts can be mounted to and pass through the transaxle in the case of a front-wheel drive configuration, or a four-wheel drive configuration, or an all-wheel drive configuration for the vehicle.
Typical four-wheel drive vehicles have their engine and transmission arranged in a longitudinal layout. In these typical vehicles, a transfer case, that is a separate powertrain component from the engine and the transmission, supplies the drive torque to each of the front and rear axles. The transfer case typically includes a gear reduction assembly that provides a high range drive ratio typically used for normal driving speeds and conditions, and a low range drive ratio usable at low driving speeds on off-road terrain, low traction surfaces, and during high torque requirement situations, as well as during other driving conditions. The longitudinal layout for the transmission and powertrain that is typically used reduces interior volume of the vehicle because the floor of the passenger compartment is raised to accommodate the bulk of the transmission and the transfer case.
Conventional front-wheel drive powertrains are mounted transversely on the vehicle within the engine compartment. As a result, there is little or no intrusion of the powertrain into the passenger compartment.
There is a trend to supplement the transversely mounted front-wheel drive powertrains with four-wheel and/or all-wheel drive capability. Such conventional vehicles typically do not include a transfer case nor do they typically provide a low range final drive ratio. The passenger compartment floor may only need to accommodate the propeller shaft and the rear differential assembly. As a result, the powertrain has little or no impact on the interior space of the passenger compartment.
Accordingly, there is a need for a four-wheel drive and/or all-wheel drive powertrain that provides a two speed final drive assembly that can be packaged substantially within the engine compartment and that can minimize intrusion into the passenger compartment of a vehicle.